Woman discovers husband's longterm affair with sister, cuts off 'supportive' mom, gets a girlfriend. AITA? UPDATED

"AITA for divorcing my husband after he cheated with my sister, cutting off my mom for supporting them, and moving on with my life?"

This has been the most traumatic year of my life, and I’m wondering if I’m being too harsh or if I’m justified in my choices. I (F35) was married to my husband (M42) for eight years. We have two kids together a son (9) and a daughter (7). I thought our life was stable and happy until everything unraveled seven months ago.

I found out that my husband was cheating on me with my younger sister (24). I didn’t discover it through subtle clues or intuition. My son overheard an inappropriate conversation between the two of them at a family gathering and came to me, confused and upset. When I confronted my husband, he denied it at first, but eventually admitted to the affair.

I was utterly shattered. But what made it even worse was that my mom sided with my husband and sister. She defended their actions, saying, “Your sister is young and doesn’t know any better,” and, “Your husband must have felt neglected to fall for someone else.” Then she had the audacity to suggest I forgive them and “keep the family together for the kids.” I was stunned and disgusted.

My dad, on the other hand, was furious. He called out my mom’s behavior, told her she was enabling betrayal, and eventually filed for divorce from her because he couldn’t tolerate her lack of morals. He’s been one of my few sources of support throughout all of this.

I filed for divorce immediately and cut off my mom and sister completely. My kids have been struggling with the fallout. My son is especially angry and has told me he doesn’t want anything to do with his dad.

My daughter is quieter but has been acting out in small ways. We’ve been going to therapy together, and I’ve been doing everything I can to help them navigate this while also trying to heal myself.

Over the past few months, I’ve started putting my life back together. I’ve focused on my kids, leaned on my dad and close friends for support, and even started dating someone new (F36). She’s been incredible—kind, understanding, and supportive. She’s great with my kids, and they’ve grown to love her, which makes me feel like I can finally see a light at the end of the tunnel.

But the chaos isn’t over. My sister’s relationship with my ex-husband has completely fallen apart (shocking, right?). Now she’s blaming my mom, saying she encouraged the whole thing. My mom, meanwhile, is blowing up my phone, accusing me of tearing the family apart by refusing to forgive them.

My mom says my new relationship is “a slap in the face” to our family and claims I’m being selfish for not letting her or my sister back into my life. To top it off, my ex-husband has been reaching out, begging for forgiveness and asking for a second chance. He’s telling me it was all a mistake and that he misses me and the kids.

My son and daughter both want nothing to do with him, but I’m conflicted about how much of a relationship (if any) they should have with their father. My dad and friends say I’m doing the right thing by cutting out toxic people and focusing on rebuilding my life.

But the guilt-tripping from my mom and sister is starting to wear me down, and I’m wondering if I’m being too harsh. Should I try to reconcile with my mom and sister for the sake of family? Should I give my ex more of a chance to be involved for the sake of the kids? AITA for divorcing my husband, cutting off my mom and sister, and moving forward with my life and new relationship?

EDIT:

I have changed my number and I’m currently moving, no I don’t speak to any of my ex husband’s family and apparently the snitch was my aunt and her husband (are we shocked?) so I’m officially not speaking to them.

And for the people complaining about the fact my kids know my girlfriend so what? my children adore her, also for the custody. It’s 60-40, meaning I can choose which schedule the kids can have with their father since I’m the primary.

No I’m not forcing my kids to not speak to their dad, they’ve told me numerous times that they don’t like going to my ex husband’s house and i respect that, i’m currently going for full custody.

For the people telling me to get a restraining order, my lawyer said they haven’t done anything to endanger my children and I so i legally can’t get one. My dad also has some suspicions that my mom cheated on him with how she was defending the affair.

UPDATE:

The people that suggested my mom may of cheated/had an affair were correct, apparently my mom cheated on my dad early in the relationship but said she “stopped” the affair when my dad found out (spoiler she didn’t). We aren’t exactly sure if my sister is my father’s child, and quite frankly we hope she isn’t.

As for my ex husband, yes he is allowed to visit his children. He just refuses to see them because my kids hate being around him, not because i’m restricting it as people are claiming.

I have 60/40 custody and the judge granted me full permission to set a schedule on when my kids see my their father as long as he isn’t completely out of their lives. It also might help that the affair he had with my sister, no one knows how long it went on but my son has spoken to me (which is hard for him) and said that his always seen his “daddy”...

...talking to my sister so it’s definitely gone on since she was early 20’s. My children are completely fine, they are currently in therapy for this and other stuff. No schoolwork has been affected, and my girlfriend certainly isn’t affecting them matter of fact they love her in the few times she is here.

For those curious, my son is turning 10 soon and he heard more than one of these conversations. He only told me about this one because he understood what they were saying, which is traumatising for a child to literally listen to.

A massive f you to any homophobes, my children adore my partner no she isn’t like a second parent to them. She also loves them as well, and is in no way trying to take a fatherly role in their life.

Here's what top commenters had to say about this one:

True-Presentation726 said:

Why are you even in communication with your mom and sister? Cut them off immediately, don't let them get in your head. They are selfish and do not have your best interests to heart. Keep on the way you are, lean on those you can trust, those who haven't betrayed you.

You do know, I hope, that neither of the vile 3 (ex, sis, mom) are ever to be trusted again, right? And please listen to your kids, keep them in therapy, and if they eventually want to see their dad, then that's the time, but if never, then that's on him. I'm sorry to read your story. Good luck moving forward with your new, better life. Keep the horrible selfish ones far away from you and the kids. NTA.

Amadeus3698 said:

NTA triple betrayal from ex husband, sister, and mother. Your sister is well enough into adulthood to have known having an affair with her BIL was going to end poorly. Family might mean cutting them more slack than you would for others but it has limits. Obviously this is way beyond that. Block her everywhere and if it’s needed get a restraining order.

Your mom is an idiot. It would have been one thing to stay on the sidelines and still talk to your sister. She likely cheated at some point and is projecting or is just delusional. Block her everywhere and if it’s needed get a restraining order.

Your ex husband is trickier. He is entitled to time with your kids. I would tell him to leave you alone unless it’s to do with the kids. You should have settled the terms of custody with the divorce. Follow the custody agreement and don’t engage otherwise. If he starts manipulating the kids, talk to the courts and see what can be done. A cheater is always a cheater.

cuddlychickk said:

NTA. You’re not wrong for divorcing your husband and cutting off your mom and sister after their betrayal. Their lack of support and enabling behavior makes them toxic. You're focusing on rebuilding your life and protecting your children, which is completely justified. You're not being harsh—you're prioritizing your well-being.

Crazy-_-boy said:

NTA. You’ve been through an absolute nightmare, and you’re handling it with way more grace than most people could. Your husband and sister betrayed you in one of the worst ways imaginable, and your mom defending them is just beyond messed up. Blood doesn’t give people a free pass to treat you like crap. Cutting them off isn’t harsh it’s protecting your peace and your kids well being.

As for your ex, actions have consequences. He made his choice, and now he has to deal with the fallout. If your kids don’t want a relationship with him, that’s valid, and it’s up to him to earn their trust back .

You’re prioritizing your kids, your healing, and your happiness, which is exactly what you should be doing. Your new relationship sounds like a positive step forward, and your mom and sister trying to guilt-trip you is just them refusing to take accountability. Stay strong you’re doing what’s best for you and your family.

HiamRipe said:

You're NTA. Focus on healing, your kids, and your supportive new relationship. Stay strong!

Kindly_Rephrase said:

NTA. Your mom’s behavior was so egregious that your dad divorced her for it. That had nothing to do with how you handled your ex and sister. Mom needs therapy and keep blocking while being strong and resilient. Those three can go chew rocks.

74Magick said:

Not at all. And tell your Mom if she wants a "slap in the face" she can come around with your sister and you can educate them on what a real "slap in the face" feels like. NTA.